A CFD technique for estimating the flow distortion effects on LiDAR measurements when made in complex flow fields

The effect of flow distortion on the measurements produced by a LiDAR or SoDAR in close proximity to either complex terrain or a structure creating localised flow distortion is difficult to determine by analytical means. Also, as LiDARs and SoDARs are not point measurement devices, the techniques they employ for velocity measurements leads to complexities in the estimation of the effect of flow distortion on the accuracy of the measurements they make. This paper presents a method by which the effect of flow distortion on measurements made by a LiDAR in a distorted flow field may be determined using computational fluid dynamics. The results show that the error created by the flow distortion will cause the vector measured by a LiDAR to differ significantly from an equivalent point measurement. However, the results of the simulation show that, if the LiDAR is being used to measure the undisturbed flow field above a structure which creates highly localised flow distortion, the LiDAR results are less affected by the distortion of the local flow field than data acquired by a point measurement technique such as a cup anemometer

Model evaluation of RIMPUFF within complex terrain using an Ar-41 radiological dataset.

The newly updated atmospheric dispersion model RIMPUFF is evaluated using routine releases of 41Ar from the former HIFAR research reactor located at the Australian Nuclear Science and Technology Organisation (ANSTO) in Sydney, Australia. Predicting radiological dispersion for emergency response at this site proves challenging due to complex topographical conditions including a steep-sided river valley located between the reactor and the nearest residents. A large number of 41Ar measurements from a network of environmental gamma detectors are used to evaluate the model under a range of atmospheric stability conditions. Topographic and meteorological influences that potentially affect a released plume, such as channelling, wind shear, local terrain slope flows and strong inversions are explored. A sensitivity analysis using various combinations of meteorological station data for model input, including vertical wind and temperature profiles, also identifies model strengths and weaknesses within the complex terrain. Various model evaluation tools, such as relevant statistical indices and gamma dose contour plots, are used to evaluate this new version of RIMPUFF for emergency response purposes at ANSTO and for inclusion in the ARGOS Decision Support System

Sustainable and personalized nutrition: From earth health to public health

Sustainable nutrition, equaling earth health, involves a personalized approach designed in terms of precision and avoidance of still cogent but unjustified dogmas, equaling public health. For instance, current dietary recommendations continue to dwell on the need to limit as much as possible the intake of saturated fatty acids (SFA), notwithstanding the mounting evidence that the effects of food on health cannot be predicted from the content of single nutrients without considering the overall macronutrient composition and the role of the food matrix. The traditional recommendation to restrict SFA ignores that their effects on health depend on the interaction between naturally occurring food components and those introduced by food processing. It is warranted to modify the still widely promoted dietary guidelines based upon such single nutrients as SFA and instead personalize dietary habits on the basis of the whole pattern of the food matrix. Accordingly, the double edge of malnutrition, that involves deficiency as well as excess and materializes in many individuals throughout their life course, might be tackled by implementing sustainability, with the additional effect of overcoming global inequalities. Within this context SFA may regain their position of tasty and cheap sources of energy to be adapted to each individual lifestyle

Excitations in antiferromagnetic cores of superconducting vortices

We study excitations of the predicted antiferromagnetically ordered vortex cores in the superconducting phase of the newly proposed SO(5) model of strongly correlated electrons. Using experimental data from the literature we show that the susceptibilities in the spin sector and the charge sector are nearly equal, and likewise for the stiffnesses. In the case of strict equality SO(5) symmetry is possible, and we find that if present the vortices give rise to an enhanced neutron scattering cross section near the so called pi resonance at 41 meV. In the case of broken SO(5) symmetry two effects are predicted. Bound excitations can exist in the vortex cores with ``high'' excitation energies slightly below 41 meV, and the massless Goldstone modes corresponding to the antiferromagnetic ordering of the core can acquire a mass and show up as core excitation with ``low'' excitation energies around 2 meV.Comment: 9 pages, RevTeX, including 3 postscript figures, submitted to Phys. Rev. B, July 10, 199